Mass. Gen. Laws ch. 268, § 34

Whoever disguises himself with intent to obstruct the due execution of the law, or to intimidate, hinder or interrupt an officer or other person in the lawful performance of his duty, or in the exercise of his rights under the constitution or laws of the commonwealth, whether such intent is effected or not, shall be punished by a fine of not more than five hundred dollars or by imprisonment for not more than one year and may if imprisoned also be bound to good behavior for one year after the expiration of such imprisonment.